• Journal of information and communication convergence engineering
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• v.6 no.2
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• pp.233-237
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• 2008

This paper presents proposal for an application (only for Windows-based Mobile) that can synchronize the Third Generation Windows-based mobile with the prescribed server. This application can be used by mobile users to send information directly to the WAS server wirelessly. In this paper a comparison between Third Generation technology and WLAN ( both are parallel technologies first one embodied by IMT-2000 standards and the second one by ITU Standards) has been made and also a comparison between Wi-Fi and Bluetooth has been made.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.210-213
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• 2004

In a switched reluctance motor drive, it is important to synchronize the stator phase excitation with the rotor position, because the position of rotor is an essential information. In the high-speed region, switching angles are fluctuated back and forth out of the preset value, which is caused by the sampling period of the microprocessor. In this paper, a low cost analog encoder to be suitable for practical applications is proposed. The validity of the proposed analog encoder with a proper logic controller is verified from the experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3C
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• pp.251-258
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• 2012

In this paper, we propose a novel method of multi-node frequency synchronization for distributed networks. The proposed method synchronizes carrier frequencies of all nodes in the network and this enables new entry node to synchronize immediately. Moreover, when several groups exist in the network, inter-group synchronization method is proposed. The proposed distributed frequency synchronization method is expected to be very useful for the military operation scenario that new node entry is in a state of flux and group merging and splitting frequently happen.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1191-1193
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• 2001

In switched reluctance motor(SRM) drive, it is necessary to synchronize the stator phase excitation with the rotor position. Therefore, the rotor position information is essential. Usually, optical encoders or resolvers are used to provide the rotor position information. These sensors are expensive and are not suitable for high speed operation. This paper proposes a new encoder for high performance excitation control of SRM. The proposed encoder has complex structures of incremental and absolute encoder. An each phase inductance profile can be synchronized with 4-bit absolute position signal and incremental pulses are used for speed detection. Low cost and simple structure are possible.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1132-1135
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• 2002

In this paper, we propose a phase-locked loop (PLL) with dual loops in which advantages of both loops can be combined. Frequency-locked loop (FLL) which is composed of two frequency-to-voltage converters (FVC) and an amplifier makes the frequency synchronize very fast and output signal is synchronized in phase with the input reference signal by charge pump PLL. This structure can improve the trade-off between acquisition behavior and locked behavior.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.509-511
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• 2006

According to the progress of multimedia technology and growth of high speed network, plenty of multimedia contents are produced and in circulation. Because of these reasons, it is required that the method which can manage efficiently and make multimedia contents, for which are saved in Storage as different used, synchronize. In this paper, the metadata schema that can manage the method with being database using each Device metadata that are produced by extracting the needed information to multimedia contents is suggested. And the method that can make synchronized multimedia contents metadata on connecting between heterogeneous devices is proposed.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.196-198
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• 2006

In this paper, a stereoscopic display system using a rotary disk tyre beam shutter and two beam projectors is proposed. It is a kind of active stereoscopic display and can be easily converted from passive stereoscopic system using polarizing filters. If it is possible to synchronize the revolution speed of the beam shutter with the integer multiple of the scanning frequency of the beam projectors, we can obtain a comparable performance with our system to an active stereoscopic system using one expensive high performance beam projector. Further, if we rotate the beam shutter at sufficiently high revolution speed, our active stereoscopic system works regardless of synchronization and thus the system is much easier to implement.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.194-196
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• 2005

The command processor in satellite handles the capability of the process of command transmitted from ground station and deliver the processed data to on board computer in satellite. The command processor is consisted of redundant box to increase the reliability and availability of the capability. At each command processor, the processing time of each command processor is different, so the mismatch of processing time makes it difficult to timely synchronize the reception to on board computer and even will be became worse under the command processor's fault. To minimize the tine loss induced by the command processor's fault on board computer must analyze the time distribution of command propagation. This paper presents the logic of minimizing the delay error of command propagation the logic of analyzing the output of command processor.

• Kyungpook Mathematical Journal
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• v.54 no.2
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• pp.293-320
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• 2014

In this paper, global chaos synchronization is investigated for WINDMI (J. C. Sprott, 2003) and Coullet (P. Coullet et al, 1979) chaotic systems using adaptive backstepping control design based on recursive feedback control. Our theorems on synchronization for WINDMI and Coullet chaotic systems are established using Lyapunov stability theory. The adaptive backstepping control links the choice of Lyapunov function with the design of a controller and guarantees global stability performance of strict-feedback chaotic systems. The adaptive backstepping control maintains the parameter vector at a predetermined desired value. The adaptive backstepping control method is effective and convenient to synchronize and estimate the parameters of the chaotic systems. Mainly, this technique gives the flexibility to construct a control law and estimate the parameter values. Numerical simulations are also given to illustrate and validate the synchronization results derived in this paper.

• ETRI Journal
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• v.29 no.6
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• pp.716-724
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• 2007

As ultra-wideband impulse radio (UWB-IR) uses short-duration impulse signals of nanoseconds, even a small number of timing errors can cause a detrimental effect on system performance. A delay-locked loop (DLL) is proposed to synchronize and reduce timing errors. The design of the DLL is vital for UWB systems. In this paper, an improved DLL is introduced to a UWB-IR time-hopping spread-spectrum system. Instead of using only two central correlator branches as in a conventional DLL, the proposed system uses two additional correlator branches with different delay parameters and different weight parameters. The performance of the proposed schemes with the optimal parameters is compared with that of traditional schemes through simulation: the proposed four-branch DLLs achieves less tracking jitter or a longer mean time to lose lock (MTLL) than the conventional two-branch DLLs if proper parameters are chosen.